Print components of an array in reverse order

Question

I wrote a code to print the components of a array in reverse order. However, it only returns 5 or 6 numbers (at most), even if I have put more numbers in it.

#include <iostream>
using namespace std;


int main()
{

    int i;
    int vet[i];

    cin >> i; /*Tamanho do array*/

    for(int t = 0; t<i; t++) /*Adiciona coisas no array*/
    {
        cin >> vet[t];
    }

    for(int f = i-1; f>=0; f--) /*Imprime o que tem dentro do array em ordem inversa*/
    {
        cout << vet[f] << " ";
    }

}

Is there anything missing?

Answer 1

Watch this:

    int i;
    int vet[i];

    cin >> i; /*Tamanho do array*/

That is, you declare the size of the array before reading this size. It should be later.

Try to do so:

#include <iostream>
using namespace std;

int main()
{

    int tamanho;
    cin >> tamanho; /*Tamanho do array*/
    int vet[tamanho];

    for (int t = 0; t < tamanho; t++) /*Adiciona coisas no array*/
    {
        cin >> vet[t];
    }

    for (int f = tamanho - 1; f >= 0; f--) /*Imprime o que tem dentro do array em ordem inversa*/
    {
        cout << vet[f] << " ";
    }
}

Note that I renamed the variable i for tamanho. Giving variables good names is important.

See here working on ideone.

Answer 2

The big problem is you’re declaring array before knowing what is the desired size for it. So first ask how many elements it should have, then declare with the informed size.

#include <iostream>
using namespace std;

int main() {
    int i;
    cin >> i;
    int vet[i];
    for (int t = 0; t < i; t++) cin >> vet[t];
    for (int f = i - 1; f >= 0; f--) cout << vet[f] << " ";
}

Behold working in the ideone. And in the repl it.. Also put on the Github for future reference.